Use the microphoneCapture a local recording, then decode when you stop.
Adaptive browser decoder
Morse Code Audio Translator & Decoder
Translate Morse code audio to text from a microphone or browser-supported file such as MP3 or WAV. Automatic mode finds a prominent CW tone, estimates WPM, and shows the detected Morse, readable text, and evidence behind the result.
Processed locally in your browser. Recordings are not uploaded by this page.
Decode Morse audio
Automatic mode estimates frequency and speed. Switch either field to Manual when a noisy or irregular recording needs correction.
The selected alphabet changes how detected dot-and-dash groups are mapped into characters. Digits remain available across supported alphabets.
Analyse an audio fileUse a browser-supported audio file such as WAV, MP3, M4A, OGG, or AAC.
No file ready? Generate “MORSE TEST” at 18 WPM and run it through the same automatic audio decoder.Ready. Use a clear CW/Morse tone for the strongest automatic decode.
Adaptive controls
Speed, tone, and volume window
Auto spacing estimate
dB
Discard quieter energydB
Clip louder energyTone on above threshold
Signal analysis
Spectrogram and Morse timing
Upload or record Morse audio to generate a real time-frequency spectrogram.
Range: 200 to 1800 Hz
How the adaptive decoder works
Read the signal, then expose the evidence
1. Find a prominent tone
The decoder scans the Morse/CW frequency range and selects the strongest candidate unless you lock the frequency manually.
2. Apply the volume window
Minimum and maximum dB controls discard energy outside the selected range. The threshold then separates tone-on frames from gaps.
3. Estimate timing
On/off runs are compared with likely 1-unit, 3-unit, and 7-unit Morse timings to estimate WPM, dits, dahs, character gaps, and word gaps.
4. Decode and diagnose
Detected groups are mapped through the selected alphabet. The spectrogram, timing barcode, confidence, and warnings let you inspect why a result succeeded or failed.
From sound to readable text
How to Use the Morse Code Audio Decoder
Upload a supported audio file or record through your microphone. The tool searches for likely CW tones, estimates speed, separates marks from gaps, and converts the signal into Morse code and readable text. Start with automatic analysis, then review the evidence before changing frequency or WPM manually.
Choose the sound source
Upload a recording or start the microphone. For live sound, place the microphone close enough to the source that the Morse signal stands out from room noise.
Run the automatic analysis
Leave Frequency and WPM on Auto when the signal settings are unknown. The decoder compares likely candidates, while manual controls let you lock values you already know.
Read both outputs
Check both the detected Morse sequence and readable text. Comparing the two helps separate character-mapping errors from earlier signal or timing problems.
Review the evidence
Before trusting the text, check Stability, ranked frequency candidates, character confidence, and the Accepted, Review, or Abstain status.
CW Decoder Online for Files and Microphone Input
This CW decoder online accepts microphone recordings and browser-supported Morse audio files. Common formats include WAV, MP3, M4A, OGG, and AAC when your browser can decode them. Support varies by browser and operating system, so WAV is a useful fallback.
WAVMP3M4AOGGAACMicrophone
The decoder works with audible International Morse or CW-style tones and can compare multiple likely frequencies. Recordings with one dominant signal are usually easier to interpret than mixes of simultaneous messages.
Why Morse audio decoding can fail
A Morse code sound decoder must identify the signal, estimate speed, classify dits and dahs, and separate element, letter, and word gaps. An error at any stage can change the final text.
- Wrong carrier: a louder whistle, harmonic, background tone, or second transmitter can pull automatic frequency selection toward the wrong signal.
- Wrong speed: an inaccurate WPM estimate can move dit, dah, letter-gap, and word-gap boundaries.
- Room echo or microphone tailing: reverberation can make marks appear longer, compress short gaps, or blur nearby boundaries.
- Noise, speech, or music: unrelated energy can fragment real marks or create false tone segments.
- Changing timing: irregular hand keying, changing WPM, clipping, or fading can make one global setting fit only part of a recording.
- Competing signals: two strong carriers can each produce readable-looking but different text.
Confidence is not a guarantee
What Accepted, Review, and Abstain mean
Readable text is not always reliable. The decoder therefore separates the raw result from its evidence status.
The leading text has strong agreement across signal, timing, and nearby-parameter checks, with no major conflicting candidate detected.
The current text leads, but some evidence conflicts. Inspect nearby frequencies, timing settings, segmentation, or uncertain characters before relying on it.
The raw text remains visible, but the decoder does not endorse it. Nearby settings may disagree, signal separation may be weak, or a competing carrier may produce different text.
Improve the source before forcing the answer
Tips for better Morse sound decoding
A clear CW signal is easier to track than several simultaneous beeps, whistles, or transmitters.
Heavy distortion can flatten the signal envelope and damage the boundaries between marks and gaps.
Background audio can create false segments around the real Morse tone. Use a cleaner source or quieter environment when possible.
A stronger direct signal can reduce the relative effect of room echo and background noise.
Choose the right Morse tool
Morse audio decoder vs Morse code translator
Use the audio decoder for sound
Choose this page for recordings, live microphone input, CW tones, or Morse beeps: sound → detected signal → timing → Morse → text.
Use the translator for text or symbols
Choose the main translator when you already have text, dots and dashes, or written Morse notation. It converts directly between text and Morse symbols.
Open Morse Code TranslatorPractice a known distress signal
Use the dedicated SOS page to hear and watch the continuous ...---... pattern, compare its timing with spaced letters, and download WAV audio.
Play SOS in Morse CodeCommon questions
Morse code audio decoder FAQ
Can I decode Morse code from an MP3 or WAV file?
Yes. WAV and MP3 are common choices, while M4A, OGG, or AAC can also work when your browser supports them. Try WAV if a compressed file will not open.
Can I decode Morse code through my microphone?
Yes. Start Listen, allow microphone access, play the Morse sound, then stop and analyse the recording. Keep the microphone close to the source and reduce background noise when possible.
Is this a live CW decoder?
It can capture live Morse or CW through your microphone, but decoding happens after you stop the recording. It is a capture-then-decode workflow, not continuous real-time text streaming.
What frequency should I use for Morse audio?
There is no single pitch for every recording. Leave Frequency on Auto when the carrier is unknown, or lock it manually when you know the source pitch.
Is my recording uploaded to a server?
No. Selected files and microphone captures are processed locally in your browser for decoding.
What does Insufficient Evidence mean?
A raw candidate exists, but the evidence is too weak or conflicting to endorse it. Nearby settings may disagree, signal separation may be poor, or another strong carrier may produce different text.